Employee Benefit Plans (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares
Beginning Balance Outstanding (in shares)	3,037
Granted (in shares)	825	501	1,026
Exercised (in shares)	(926)
Forfeited (in shares)	(92)
Ending Balance Outstanding (in shares)	2,844	3,037
Vested and expected to vest at December 31, 2016 (in shares)	2,715
Exercisable at December 31, 2016 (in shares)	1,484
Weighted average exercise price
Balance Outstanding (in dollars per share)	$ 33.74	$ 25.18
Granted (in dollars per share)	48.36
Exercised (in dollars per share)	17.36
Forfeited (in dollars per share)	47.01
Vested and expected to vest at December 31, 2016 (in dollars per share)	33.12
Exercisable at December 31, 2016 (in dollars per share)	$ 21.81
Remaining contractual term (years)
Outstanding	7 years	6 years 4 months 28 days
Vested and expected to vest at December 31, 2016	6 years 11 months 1 day
Exercisable at December 31, 2016	5 years 5 months 12 days
Aggregate intrinsic value
Outstanding	$ 110,256	$ 65,229
Vested and expected to vest at December 31, 2016	106,927
Exercisable at December 31, 2016	$ 75,213